1. Field of the Invention
The present invention relates to an information recording system suitable for use with a personal computer, a portable information terminal and the like, and more particularly, to a flexible recording system in which a recording medium is exchangeable, and to a flexible disk drive and a recording disk.
2. Description of the Related Art
FIG. 24 is a fragmentarily sectional perspective view showing a conventional flexible disk drive which is disclosed in a Japanese Patent Laid-Open No. Hei 06-119699. FIG. 25 is a cross section taken along line AAxe2x80x2 in FIG. 24.
In FIG. 24, a disk-shaped recording medium is received in and protected by a recording medium cartridge 50a. The recording medium cartridge 50a is provided with a window (not shown) and a shutter (not shown) for opening and closing the window. Also, the recording medium cartridge 50a is provided on its bottom with a write-protect hole (not shown) for preventing erasure of information recorded in the recording medium 50 and writing of new information therein, and a slide member (not shown) adapted to dose the write-protect hole for enabling information in the recording medium 50 to be erased or new information to be recorded thereinto.
The flexible disk drive 51 (hereinafter referred to as FDD) includes a read/write head 52 for recording information into the recording medium 50 and reproducing information recorded therein, and a carriage 53 for moving the read/write head 52 to a predetermined record track (not shown) of the recording medium 50 under the action of a stepping motor 55. A head arm 54 holding the read/write head 52 is coupled to and supported by the carriage 53.
The FDD 51 further has a recording medium drive motor 56 for driving the recording medium 50 to rotate, and a control board 57 for controlling the read/write head 52, the stepping motor 55 and the recording medium drive motor 56. The control board 57 has a detection switch (not shown) for detecting that the recording medium 50 has been mounted or loaded into the FDD 51, and a write-protect switch (not shown) for detecting whether writing information into the recording medium 50 is permitted.
A cartridge holder 58 for holding the recording medium 50 has a cam follower 58a and a shutter opener 58b. A slide cam 59 has a cam groove 59a which is adapted to be engaged with the cam follower 58a to cause the cartridge holder 58 to move up and down. An eject button 59b is provided on the slide cam 59. The operation of the slide cam 59 is restricted by a latch lever 60.
The above-described components 52 through 60 are housed in or mounted to a frame 61 which has a fitting part 61 a for mounting an external dedicated slot 62 An upper cover or shield 63 is mounted on an upper portion of the frame 61.
As shown in FIG. 25, the recording medium 50 is fixedly secured at its center to a hub 50b which has two holes 50b1, 50b2. The cartridge 50a has a window 50c formed therethrough, a shutter 50d for opening and closing the window 50c, a write-protect hole 50e and a slide member 50f. 
The recording medium drive motor 56 has a rotor 56a, a chucking portion 56b fixedly secured to the rotor 56a and having a magnetized portion contacting the hub 50b, a drive pin 56c provided on the chucking portion 56b, a rotation shaft or spindle shaft 56d fixedly attached to the chucking portion 56b, a bearing 56e for rotatably supporting the spindle shaft 56d, a stationary member in the form of a stator 56f, and a coil 56g wound around the stator 56f. 
The control board 57 has a disk-in switch 57a with an operating portion 57a1 for detecting that the recording medium 50 is set at a read/write position in the FDD 51. The control board 57 also has a write protect switch 57b with an operating portion 57b1 for detecting the write protection of the recording medium 50. Here, permission of writing (recording and erasure of information are permitted) is in a state that the operating portion 57b1 at the distal end of the write-protect switch 57b is pushed into the write-protect switch 57 by means of the slide member 50f. On the other hand, write protection is in a state that the operating portion 57b1 is not pushed in by the slide member 50f. 
The disk-in switch 57a is of the same or like configuration as the write-protect switch 57b. When the recording medium 50 is mounted in the FDD 51, the operating portion 57a1 of the disk-in switch 57a is pushed into the disk-in switch 57a by means of the recording medium cartridge 50a. On the contrary, when the recording medium 50 is not mounted in the FDD) 51, the operating portion 57a1 is not pushed in.
The operation of the conventional flexible disk drive will be explained while referring to FIGS. 24 and 25.
At first, a transition from the unloaded state where it is not possible to read from and write on the recording medium 50 to the loaded state where it is possible to read from and write on the recording medium 50 is explained below.
When the recording medium 50 is not inserted into the FDD 51, the cam follower 58a of the cartridge holder 58 is pushed up by the cam groove 59a of the slide cam 59, so the cartridge holder 58 is positioned above the spindle shaft 56d of the recording medium drive motor 56, i.e., at the side B.
Then, the recording medium cartridge 50a is further moved in a direction C in FIG. 24 so as to be inserted into the cartridge holder 58, the shutter 50d is opened by the shutter opener 58b, so that the read/write head 52 can reproduce information from the recording medium 50. At this time, the distal end of the recording medium 50 comes in contact with the latch lever 60, thus causing it to rotate.
Owing to the rotation of the latch lever 60, the slide cam 59 is released from restriction of the latch lever 60, and forced to move in a direction D under the biasing force of an unillustrated spring. Since the cam groove 59a in the slide cam 59 is in engagement with the cam follower 58a of the cartridge holder 58, te cartridge holder 58 is displaced in a direction E in accordance with the movement of the cam groove 59a in the slide cam 59, while holding the recording medium 50.
When the recording medium 50 is lowered to a predetermined location with the movement of the cartridge holder 58 in the direction E, the hole 50b2 in the hub 50b holding the recording medium 50 is engaged with the spindle shaft 56d, whereby the drive pin 56c is fitted into the hole 51b1 and the hub 50b is magnetically attracted by the chucking portion 56b, thus making it possible for the recording medium 50 to be rotated by means of the recording medium drive motor 56.
On the other hand, in accordance with the movement of the recording medium 50 in the direction E, the operating portion 57a1 of the disk-in switch 57a is pushed into the disk-in switch 57a by means of the recording medium cartridge 50a, so that the control board 57 generates a signal indicative of the loading or mounting of the recording medium 50 to an unillustrated external device. Similarly, the control board 57 generating a signal indicative of write protection or permission to the unillustrated external device, depending upon whether the operating portion 57b1 of the write-protect switch 57b is pushed into the write-protect switch 57b. 
Thereafter, the read/write head 52 supported by the carriage 53 can contact the recording surface of the recording medium 50 through the window 50c for reproducing information therefrom.
Next, a transition from the loaded state to the unloaded state of the recording medium 50 will be explained.
By pressing the eject button 59b to a fixed position in the direction C, the slide cam 59 is moved similarly, so the cartridge holder 58 is moved or raised in the direction B along the cam groove 59a. When the hub 50b of the recording medium 50, moving with the cartridge holder 58, comes to a position to the direction B from the drive pin 56c and the spindle shaft 56d, the respective engagements between the hole 51b1, 50b2 and the drive pin 56c and the spindle shaft 56d are released, and hence the engagement between the shutter 50d and the shutter opener 58b is also released, thus closing the shutter 50d. 
As a result, the recording medium 50 is moved in the direction D by the shutter opener 58b and the latch lever 60 which are both biased by unillustrated springs, so that it is ejected from the cartridge holder 58.
In addition, the slide cam 59 is latched by the latch lever 60 and restricted in its movement, and the cartridge holder 58 is held at a position to the direction B from the spindle shaft 56d through engagement between the cam follower 58a and the cam groove 59a in the slide cam 59.
FIGS. 26 through 29 illustrate another conventional flexible recording system which is disclosed, for example, in Japanese Patent Application No. Hei 7-302979 (1995-302979). FIG. 26 is a perspective view showing an overall construction thereof; FIG. 27 is a cross-sectional side view showing the system with a recording disk mounted thereon, being sectioned by a center line thereof; FIG. 28 is a partially broken plan view of the same; and FIG. 29 is a cross section taken along line BBxe2x80x2 of FIG. 28.
In FIG. 26, a disk-shaped recording medium 70 is received in a cartridge 70a, and is fixedly attached to a hub 70b. The cartridge 70a has a window (not shown) which is opened or closed by a shutter 70c. The recording medium 70 is mounted into a flexible disk drive 71 (hereinafter simply referred to as FDD) so that information is recorded into or reproduced from the recording medium 70 by means of the FDD 71. A flexible recording system, generally designated at 90, comprises the recording medium 70 and the flexible disk drive device 71. The system 90 is provided with a general-purpose slot 91 of a PCMCIA (Personal Computer Memory Card Association) type 2 standard which is adapted to be mounted on an information processing device (not shown) such as a portable information peripheral terminal and the like. The slot 91 comprises a mounting portion 91a for mounting therein the FDD 71 and an eject button 91b for ejecting or discharging the FDD 71 therefrom.
In FIG. 27, a limiting or restrictive member 70a1 is provided on the cartridge 70a for rotatably supporting the hub 70b and limiting or suppressing movements or displacements thereof. The hub 70b is positioned at the center of the recording medium 70 and fixedly secured thereto. The hub 70b has a hole or aperture 70b1 formed therethrough, three protrusions or convexities 70b2 disposed around the center of the hole 70b1 at equal circumferential intervals (i.e., spaced an angle of 120 degrees from each other), and a window or opening 70d formed therein which is opened or closed by the shutter 70c. 
Also, a read/write head 72 is provided for recording information into the recording medium 70 or reproducing information recorded thereon. A cartridge 73 is driven to move the read/write head 72 to a predetermined recording track (not shown) under the action of a stepping drive motor 75 (see FIG. 28). A head arm 74 is supported at its one end by the carriage 73.
A recording medium drive motor 76 serves to rotate the recording medium 70 and has a rotating member in the form of a rotor 76a and a chucking portion 76b which acts to fix the rotor 76a. A part of the chucking portion 76b that is in contact with the hub 70b is magnetized to attract and hold the hub 70b in position through a magnetic force. The chucking portion 76b is provided with concavities 76c into which the convexities 70b2 are engaged. The recording medium drive motor 76 has a rotation shaft 76d which is formed into a spherical shape and movable in a direction indicated at B or E. The rotation shaft 76d is rotatably supported by bearings 76e. The recording medium drive motor 76 further comprises a stationary member in the form of a stator 76f, a coil 76g wound around the stator 76f, and a spring 76h for urging the rotation shaft 76d toward the direction or side B.
In FIG. 28, the recording medium cartridge 70a is provided with a latch groove 70a2, and a slide switch 70e for discriminating a write-protect state of the recording medium 70 in which erasure and recording of information on the recording medium 70 are inhibited. A button 70e1 is formed on the slide switch 70e in such a manner as to protrude outwardly from an upper surface of the recording medium cartridge 70a for causing a sliding motion of the slide switch 70e. A hookshaped engagement portion or member 70e2 is formed on the slide switch 70e. 
The slide switch 70e has a connector 70e3 made of a conductive metal and formed into a bifurcated configuration having two legs with protrusions 70e4, 70e5, respectively, formed thereon, an end of one of the two connector legs being elastic. The recording medium cartridge 70a is formed integrally with a pair of connector plates 70e6, 70e7 which are respectively made of a conductive metal and formed into a planar configuration. The connector plates 70e6, 70e7 each have one surface exposed outside from a lower surface of the recording medium cartridge 70a and the other surface adapted to be in contact with the protrusions 70e4, 70e5, respectively. A position limiting member 70e8 is provided on the recording medium cartridge 70a for limiting, upon engagement with the engagement member 70e2, the movement of the slide switch 70e. 
The FDD 71 further comprises a stepping drive motor 75 for driving the carriage 73 in a stepwise manner, and a control board 77 for controlling te read/write head 72, the stepping drive motor 75 and the recording medium drive motor 76.
In FIG. 29, a write-protect detector 78 is electrically connected with the control board 77 for detecting whether writing of information into the recording medium 70 is protected or permitted. The write-protect detector 78 has a pair of connector terminals 78a, 78b which are disposed in a face-to-face relation with respect to the connector plates 70e6, 70e7, respectively. The connector terminals 78a, 78b are fixedly secured to a switch holder 78c formed of a non-conductive material such as plastic resin and the like, in such a manner that they are not in contact with each other.
In FIG. 28, the FDD 71 further comprises a recording medium eject mechanism 79 for ejecting or discharging the recording medium 70 from the FDD 71. The recording medium eject mechanism 79 has a biasing member 79a for biasing or urging the recording medium 70 in a direction D to eject or discharge it, a shaft member 79b movable along an inserting or loading direction C or the ejecting or ejecting direction D, a button 79c fixedly mounted on the shaft member 79b at its one end disposed in the ejecting direction D, a latch 79d for limiting the movement of the recording medium 70, and a frame 80 which receives some of the above components 72 through 79 or to which the other of them are mounted An upper cover 81 is attached to the frame 80. Here, it is to be noted that the FDD 71 includes the above components 72 through 81.
Now, the operation of the above-mentioned conventional flexible recording system will be described below.
First, the slide switch 70e is moved to a predetermined position as shown in FIG. 28 through a manipulation of the button 70e1, and set there. At this position, the protrusions 70e4, 70e5 of the connector 70e3 are placed into contact with the connector plates 70e6, 7037, respectively, and thus electrically connected thereto.
Subsequently, as shown in FIG. 26, the recording medium 70 is moved from an initial state in which it is not loaded in the FDD 71 in the loading direction C so that it is inserted into the FDD 71 with the lower surface of the recording medium cartridge 70a being in flush with the hub 70b, as seen from FIG. 27.
As the recording medium 70 is inserted into the FDD 71, the rotation shaft 76d is thereby caused to move in a direction E indicated by a broken line. When the recording medium 70 being further inserted has reached a position in which the hole 70b1 in the hub 70b opposes to the rotation shaft 76d, the rotation shaft 76d is caused to move in the direction B in FIG. 27 under the biasing force of the spring 76h, so that it is fitted into the hole 70b1 in the hub 70b which is in flush with the lower surface of the recording medium cartridge 70a, whereupon by rotation of the chucking portion 76b, the convexities 70b2 of the hub 70b are placed into fitting engagement with the concavities 76c in the chucking portion 76b, so that the recording medium 70 is placed in position and held there through the hub 70b under the action of the magnetic force of the chucking portion 76b. 
At this time, the recording medium cartridge 70a forces the latch 79d to rotate, thus unlatching the shaft member 79b. As a result, the shaft member 79b is moved in the ejecting direction D, placing a pin of the latch 79d into fitting engagement with the latch groove 70a2, and positioning the recording medium cartridge 70a in place to limit or restrict its movement. In this state, the biasing member 79a is in engagement with the groove in the recording medium cartridge 70a, urging it in the ejecting direction D.
Also, upon insertion of the recording medium 70, the shutter 70d is opened to permit the read/write head 72 to contact the recording surface of the recording medium 70 through the window 70c, so that information can be recorded into or reproduced from the recording medium 70.
Then, the operation of the write-protect detector 78 will be described. In a state where the recording medium cartridge 70a is positioned in place within the FDD 71 and thus properly mounted therein, the connector plates 70e6, 70e7 are in contact with the connector terminals 78a, 78b, respectively, of the write-protect detector 78. Since the connector 70e3 is in contact with the connector terminals 78a, 78b by way of the protrusions 70e4, 70e5 to be electrically connected thereto, the connector terminals 78a, 78b are electrically connected to each other. The control board 77 detects the conductive state of the write-protect detector 78 and controls, as a result of such detection, the operation of the read/write head 72.
It is generally determined that writing is permitted in case of the conductive state, but not in the non-conductive state. However, this can be reversed.
Although not illustrated, in order to make the connector terminals 78a, 78b non-conductive, the button 70e1 is moved to the right in FIG. 28, causing the engagement member 70e2 into engagement with the position limiting member 70e8, whereby the protrusion 70e4 is abutted against the connector plates 70e7, rendering the connector plate 70e6 into an electrically disconnected state to the connector 70e3. As a result, the connector terminals 78a, 78b of the write-protect detector 78 are electrically disconnected from each other.
Recently, miniaturization of an information processing device, in particular a portable information terminal, is advanced, and hence reduction in size of a flexible disk drive such as the FDD 51 as used in these devices is also advanced. However, the size of the recording medium 50 employed with the FDD 51 is generally 3.5 inches and the dimensions of the FDD 51 are 100 mm wide, 130 mm long, and 17.5 mm-250 mm thick.
In comparison with this, a memory card such as a so-called PC card, the specifications for which are decided by PCMICA (Personal Computer Memory Card Association) in the United States of America, is 54.0 mm wide, but varies in thickness, i.e., 3.3 mm, 5.0 mm, 10.5 mm, and so on. A recording device of such a small size is very effective for further miniaturization of the portable information terminal, but with such a memory card containing an IC memory as a recording medium, it is not possible to exchange the IC memory alone, but instead the IC memory card itself must be exchanged as a whole. In addition, since the IC memory itself is expensive, the price of the IC memory card is also high. Accordingly, the cost gets expensive when the IC memory card is used to exchange the recording medium.
In these circumstances, it may be considered that the FDD 51, for which the recording medium 50 used therein is low in price and easy to exchange, is made smaller in size and thinner, for this purpose. In this regard, however, upon mounting or loading the recording medium 50 into the FDD 51, the recording medium 50 is moved in the thickness direction by means of the cartridge holder 58 and the slide cam 59 so as to bring the drive pin 56c and the spindle shaft 56d of the recording medium drive motor 56 into fitting engagement with the corresponding holes 50b1, 50b2 in the hub 50b of the recording medium 50, thus holding the recording medium 50 in a rotatable manner. Consequently, in order to ensure engagement between the hub 50b and spindle shaft 56d or the drive pin 56c upon loading and unloading of the recording medium 50, an ample space is required in the thickness direction, making it difficult to reduce the overall size and thickness of the FDD 51.
Furthermore, the second-mentioned conventional flexible recording system has the following problems. In order to detect whether recording or erasure of information into or from the recording medium 70 is permitted, the recording medium 70 used for the conventional flexible recording system is provided with the slide switch 70e which is formed of a bifurcated metal plate and has the connector 70e3 with the protrusions 70e4, 70e5, and the FDD 71 is provided with the write-protect detector 78 having the connector terminals 78a, 78b in contact with the connector plates 70e6, 70e7, respectively. Thus, this flexible recording system is complicated in its construction.
Upon mounting the recording medium 70 into the FDD 71, the connector plates 70e6, 70e7 are in sliding contact with the connector plates 70e6, 70e7, so that both or one of them are(is) subjected to wearing, giving rise to a problem of poor electrical contact with the result that normal or correct detection of write protection of the recording medium 70 sometimes becomes impossible.
Since there is no special means for detecting the presence and absence of the recording medium 70 in the FDD 71, such a detection is made indirectly by whether or not the read/write head 72 can extract a reproducing signal from the recording medium 70, so electrical circuitry used for this purpose becomes necessarily complicated in construction, and there is a fear that if no information is recorded in the recording medium 70, it might be mistakenly determined that no recording medium 70 is present in the FDD 71.
Moreover, owing to the spherical configuration of the rotation shaft 76d, the state of engagement of the rotation shaft 76d with the hole 70b1 in the hub 70b is liable to be unstable, so it is difficult for the recording medium 70 to be rotated in a stable manner. Still further, since positioning in the rotating direction of the recording medium 70 is effected by engagement of the rotation shaft 76d with the hole 70b1 in the hub 70b and engagement of the convexities 70b2 of the hub 70b with the concavities 76c in the chucking portion 76b, accuracy of such positioning is not good.
In view of the above, the present invention is intended to obviate the above-mentioned various problems encountered with the conventional flexible recording systems.
An object of the present invention is to provide a novel and improved flexible recording system, a flexible disk drive and a recording disk in which a recording medium can be loaded and unloaded without requiring its movement in a thickness direction of a flexible disk drive.
Another object of the prevent invention is to provide a novel and improved flexible recording system, a flexible disk drive and a recording disk which can be reduced in size to such an extent as a memory card while ensuring satisfactory reliability in operation.
A further object of the present invention is to provide a novel and improved flexible recording system, a flexible disk drive, and a recording disk in which upon insertion of a recording medium into a flexible disk drive, a write-protect detector is not subjected to wearing so that it can precisely detect the state (i.e., write protection or permission) of the recording medium as well as the presence and absence thereof.
According to one aspect of the present invention, there is provided a flexible recording system comprising:
a recording disk having a disk-shaped recording medium and a recording medium cartridge rotatably receiving therein the recording medium; and
a flexible disk drive;
the flexible disk drive comprising:
a magnetic head for recording information into the recording medium or reproducing information recorded in the recording medium;
a carriage mechanism for moving the magnetic head;
a recording medium drive motor for driving the recording medium to rotate;
a frame having an insertion opening through which the recording disk is inserted, and a recording medium mounting portion formed adjacent the insertion opening in a direction in which the recording disk is inserted for mounting thereon the recording disk; and
a recording-disk ejection mechanism for ejecting the recording disk from the frame;
wherein the recording disk has a write-protect instructing member which comprises a hole formed in an end face of the recording medium cartridge disposed at one side thereof from which the recording disk is inserted into the frame, and means for opening and closing the hole; and
wherein the flexible disk drive has a write-protect detector provided on the disk mounting portion at its one end from which the recording disk is inserted into the flexible disk drive for detecting permission or inhibition of writing into the recording medium based on an open or closed state of the hole.
In a preferred form of the flexible recording system, the write-protect detector has a first detection pin which is projected in an ejecting direction in which the recording disk is ejected from the flexible disk drive, and which is movable in an inserting direction in which the recording disk is inserted into the flexible disk drive, and the write-protect detector detects an open or closed state of the hole based on whether the first detection pin is pushed by the means.
In another preferred form of the flexible recording system, the flexible disk drive has a recording disk detector provided at the disk-inserting direction side end of the disk mounting portion for detecting the presence or absence of the recording disk.
In a further preferred form of the flexible recording system, the recording disk detector has a second detection pin which is projected in an ejecting direction in which the recording disk is ejected from the flexible disk drive, and which is movable in an inserting direction in which the recording disk is inserted into the flexible disk drive, and the recording disk detector detects the presence or absence of the recording disk based on whether the second detection pin is pushed by the recording disk.
In a still further preferred form of the flexible recording system, the write-protect detector and the recording disk detector are integrally formed into a single housing, and the first detection pin and the second detection pin are disposed in opposition to the end face of the recording disk.
In a yet further preferred form of the flexible recording system, the means for opening and closing the hole comprises a spacer removably fitted in the hole.
In a further preferred form of the flexible recording system, the means for opening and closing the hole comprises a sliding lid movable along the end face of the recording medium cartridge for opening and closing the hole.
In a further preferred form of the flexible recording system, the recording disk further has a hub to which the recording medium is fixedly secured and which is received in the recording medium cartridge and supported by a support shaft for movement in a direction perpendicular to the recording surface of the recording medium, and the recording medium cartridge has an opening through which a surface of the hub is protruded outwardly of the recording medium cartridge, and the recording medium drive motor has a drawing member for drawing the hub and rotates the recording medium while holding the surface of the hub protruded from the opening outwardly of the recording medium cartridge.
In a further preferred form of the flexible recording system, the recording medium drive motor has a cylindrical rotation shaft of a predetermined length along an axial direction thereof movable therealong and adapted to be displaced toward the recording disk to engage into an axial hole in the hub.
In a further preferred form of the flexible recording system, the rotation shaft of the recording medium drive motor is urged toward the recording disk by means of a spring.
In a further preferred form of the flexible recording system, the recording medium drive motor has a drive pin disposed radially of the rotation shaft for movement therealong and adapted to engage the hub for driving the recording medium to rotate.
In a further preferred form of the flexible recording system, the rotation shaft and the drive pin of the recording medium drive motor are urged toward the recording disk by one and the same spring.
In a further preferred form of the flexible recording system, the hub has a first annular engagement portion having a center thereof on a center line passing through a center of the recording medium, and a reception chamber formed between the first engagement portion and the surface of the hub, and the recording disk has a position adjusting member which is received in the reception chamber and which has a second engagement portion engageable with the rotation shaft of the recording medium drive motor and a third engagement portion engageable with the first engagement portion so as to position the center thereof on an axis of rotation of the recording medium, the position adjusting member being held at a predetermined position of the rotation shaft through engagement of the second engagement portion with the rotation shaft and positioning the center of the first engagement portion on the axis of rotation through the third engagement portion.
In a further preferred form of the flexible recording system, the rotation shaft of the recording medium drive motor has a chamfered portion formed at one end thereof near the recording disk, and the second engagement portion of the position adjusting member is formed into a configuration to match the chamfered portion.
According to another aspect of the present invention, there is provided a flexible disk drive comprising:
a magnetic head for recording information into a recording medium of a recording disk or reproducing information recorded in the recording medium;
a carriage mechanism for moving the magnetic head;
a recording medium drive motor for driving the recording medium to rotate;
a frame having an insertion opening through which the recording disk is inserted, and a recording medium mounting portion formed adjacent the insertion opening in a direction in which the recording disk is inserted for mounting thereon the recording disk; and
a recording-disk ejection mechanism for ejecting the recording disk from the frame;
a recording medium detector provided on the disk mounting portion at its one end from which the recording disk is inserted into the flexible disk drive for detecting the presence or absence of the recording medium; and
a write-protect detector provided on the disk mounting portion at its one end from which the recording disk is inserted into the flexible disk drive for detecting permission or inhibition of writing information into or erasing information from the recording medium.
In a preferred form of the flexible disk drive, the recording medium drive motor has a cylindrical rotation shaft of a predetermined length along an axial direction thereof, and a table supporting the rotation shaft for movement along the axial direction and having a drawing member for drawing the hub of the recording medium outwardly of the recording medium cartridge, the recording medium drive motor being adapted to draw the hub to protrude and hold it outwardly of the recording medium cartridge and at the same time to displace the rotation shaft toward the recording medium to engage it into an axial hole in the hub.
In another preferred form of the flexible disk drive, the rotation shaft of the recording medium drive motor is urged toward the recording medium by means of a spring.
In a further preferred form of the flexible disk drive, the recording medium drive motor has a drive pin disposed radially of the rotation shaft for movement therealong and adapted to engage the hub for driving the recording medium to rotate.
In a still further preferred form of the flexible disk drive, the rotation shaft and the drive pin of the recording medium drive motor are urged toward the recording disk by one and the same spring,
According to a further aspect of the present invention, there is provided a recording disk comprising:
a disk-shaped recording medium;
a recording medium cartridge rotatably receiving therein the recording medium; and
a write-protect instructing member having a hole formed in an inserting direction side end face of the recording medium cartridge, and means for opening and closing the hole.
In a preferred form of the recording disk, the means for opening and closing the hole comprises a spacer removably fitted in the hole.
In another preferred form of the recording disk, the means for opening and closing the hole comprises a sliding lid movable along the end face of the recording medium cartridge for opening and closing the hole.
In a still further preferred form of the recording disk, the recording disk further comprises a hub to which the recording medium is fixedly secured and which is received in the recording medium cartridge and supported by a support shaft for movement in a direction perpendicular to the recording surface of the recording medium, wherein the recording medium cartridge has an opening through which a surface of te hub is protruded outwardly of the recording medium cartridge.
In a yet further preferred form of the recording disk, the recording disk further comprises a position adjusting member for adjusting the position of the recording medium through the hub such that an axis of rotation of the recording medium rotated by the recording medium drive motor substantially coincides with the center of the recording medium.
In a further preferred form of the recording disk, the hub has a first annular engagement portion having a center thereof on a center line passing through a center of the recording medium, and a reception chamber formed between the fist engagement portion and the surface of the hub, and the position adjusting member is received in the reception chamber and has a second engagement portion engageable with the rotation shaft of the recording medium drive motor and a third engagement portion engageable with the first engagement portion so as to position the center thereof on an axis of rotation of the recording medium, the position adjusting member being held at a predetermined position of the rotation shaft through engagement of the second engagement portion with the rotation shaft and positioning the center of the first engagement portion on the axis of rotation through the third engagement portion.
In a further preferred form of the recording disk, the first engagement portion of the hub and the third engagement portion of the position adjusting member have substantially the same diameter, and the first engagement portion or the second engagement portion is of a cone-shaped configuration.
The above and other objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments of the invention take in conjunction with the accompanying drawings.